System and method for automated collection and analysis of patient information retrieved from an implantable medical device for remote patient care

ABSTRACT

A system and method for automated collection and analysis of patient information retrieved from a medical device adapted to be implanted in a patient for remote patient care is described. A set of collected measures is periodically received from the medical device adapted to be implanted over a communications link which is interfaced to a network server. The collected measures set includes individual measures which each relate to patient information recorded by the medical device adapted to be implanted for an individual patient. The collected measures set is stored into a patient care record for the individual patient within a database server organized to store one or more patient care records. Each patient care record includes a plurality of the collected measures sets. One or more of the collected measures sets in the patient care record for the individual patient is analyzed relative to one or more other collected measures sets stored in the database server to determine a patient status indicator.

CROSS REFERENCE TO RELATED APPLICATION

This patent application is a divisional of U.S. patent application, Ser.No. 09/324,894, filed Jun. 3, 1999, now U.S. Pat. No. 6,312,378, thepriority date of which is claimed and the disclosure of which isincorporated by reference.

FIELD OF THE INVENTION

The present invention relates in general to automated data collectionand analysis, and, in particular, to a system and method for automatedcollection and analysis of patient information retrieved from animplantable medical device for remote patient care.

BACKGROUND OF THE INVENTION

Implantable pulse generators (IPGs) are medical devices commonly used totreat irregular heartbeats, known as arrhythmias. There are two basictypes. Cardiac pacemakers are used to manage bradycardia, an abnormallyslow or irregular heartbeat. Left untreated, bradycardia can causesymptoms such as fatigue, dizziness, and fainting. Implantablecardioverter defibrillators (ICDs) are used to treat tachycardia, heartrhythms that are abnormally fast and life threatening. Tachycardia canresult in sudden cardiac death (SCD).

Pacemakers and ICDs are increasingly being equipped with an on-board,volatile memory in which telemetered signals can be stored for laterretrieval and analysis. Typically, the telemetered signals providepatient device information regarding atrial electrical activity,ventricular electrical activity, time of day, activity level, cardiacoutput, oxygen level, cardiovascular pressure measures, pulmonarymeasures, and any interventions made on a per heartbeat or binnedaverage basis. In addition, a growing class of cardiac medical devices,including implantable heart failure monitors, implantable eventmonitors, cardiovascular monitors, and therapy devices, are being usedto provide similar stored device information. These devices are able tostore approximately thirty minutes of per heartbeat data. Telemeteredsignals are also stored in a broader class of monitors and therapeuticdevices for other areas of medicine, including metabolism,endocrinology, hematology, neurology, muscular, gastrointestinal,genital-urology, ocular, auditory, and the like.

Presently, stored device information is retrieved using a proprietaryinterrogator or programmer, often during a clinic visit or following adevice event. The volume of data retrieved from a single deviceinterrogation “snapshot” can be large and proper interpretation andanalysis can require significant physician time and detailedsubspecialty knowledge, particularly by cardiologists and cardiacelectrophysiologists. The sequential logging and analysis of regularlyscheduled interrogations can create an opportunity for recognizingsubtle and incremental changes in patient condition otherwiseundetectable by inspection of a single “snapshot.” However, presentapproaches to data interpretation and understanding and practicallimitations on time and physician availability make such analysisimpracticable.

A prior art system for collecting and analyzing pacemaker and ICDtelemetered signals in a clinical or office setting is the Model 9790Programmer, manufactured by Medtronic, Inc., Minneapolis, Minn. Thisprogrammer can be used to retrieve data, such as patientelectrocardiogram and any measured physiological conditions, collectedby the IPG for recordation, display and printing. The retrieved data isdisplayed in chronological order and analyzed by a physician. Comparableprior art systems are available from other IPG manufacturers, such asthe Model 2901 Programmer Recorder Monitor, manufactured by GuidantCorporation, Indianapolis, Ind., which includes a removable floppydiskette mechanism for patient data storage. These prior art systemslack remote communications facilities and must be operated with thepatient present. These systems present a limited analysis of thecollected data based on a single device interrogation and lack thecapability to recognize trends in the data spanning multiple episodesover time or relative to a disease specific peer group.

A prior art system for locating and communicating with a remote medicaldevice implanted in an ambulatory patient is disclosed in U.S. Pat. No.5,752,976 ('976). The implanted device includes a telemetry transceiverfor communicating data and operating instructions between the implanteddevice and an external patient communications device. The communicationsdevice includes a communication link to a remote medical supportnetwork, a global positioning satellite receiver, and a patientactivated link for permitting patient initiated communication with themedical support network.

Related prior art systems for remotely communicating with and receivingtelemetered signals from a medical device are disclosed in U.S. Pat.Nos. 5,113,869 ('869) and 5,336,245 ('245). In the '869 patent, animplanted AECG monitor can be automatically interrogated at preset timesof day to telemeter out accumulated data to a telephonic communicator ora full disclosure recorder. The communicator can be automaticallytriggered to establish a telephonic communication link and transmit theaccumulated data to an office or clinic through a modem. In the '245patent, telemetered data is downloaded to a larger capacity, externaldata recorder and is forwarded to a clinic using an auto-dialer and faxmodem operating in a personal computer-based programmer/interrogator.However, the '976 telemetry transceiver, '869 communicator, and '245programmer/interrogator are limited to facilitating communication andtransferal of downloaded patient data and do not include an ability toautomatically track, recognize, and analyze trends in the data itself.

Thus, there is a need for a system and method for providing continuousretrieval, transferal, and automated analysis of retrieved implantablemedical device information, such as telemetered signals, retrieved ingeneral from a broad class of implantable medical devices and, inparticular, from IPGs and cardiovascular monitors. Preferably, theautomated analysis would include recognizing a trend and determiningwhether medical intervention is necessary.

There is a further need for a system and method that would allowconsideration of sets of collected measures, both actual and derived,from multiple device interrogations. These collected measures sets couldthen be compared and analyzed against short and long term periods ofobservation.

There is a further need for a system and method that would enable themeasures sets for an individual patient to be self-referenced andcross-referenced to similar or dissimilar patients and to the generalpatient population. Preferably, the historical collected measures setsof an individual patient could be compared and analyzed against those ofother patients in general or of a disease specific peer group inparticular.

SUMMARY OF THE INVENTION

The present invention provides a system and method for automatedcollection and analysis of patient information retrieved from animplantable medical device for remote patient care. The patient deviceinformation relates to individual measures recorded by and retrievedfrom implantable medical devices, such as IPGs and monitors. The patientdevice information is received on a regular, e.g., daily, basis as setsof collected measures which are stored along with other patient recordsin a database. The information can be analyzed in an automated fashionand feedback provided to the patient at any time and in any location.

An embodiment of the present invention is a system, method, andcomputer-readable storage medium holding code for automated collectionand analysis of patient information retrieved from a medical deviceadapted to be implanted in a patient for remote patient care. A set ofcollected measures is periodically received from the medical deviceadapted to be implanted over a communications link which is interfacedto a network server. The collected measures set includes individualmeasures which each relate to patient information recorded by themedical device adapted to be implanted for an individual patient. Thecollected measures set is stored into a patient care record for theindividual patient within a database server organized to store one ormore patient care records. Each patient care record includes a pluralityof the collected measures sets. One or more of the collected measuressets in the patient care record for the individual patient is analyzedrelative to one or more other collected measures sets stored in thedatabase server to determine a patient status indicator. The patientstatus indicators are then triaged and prioritized for an appropriatelevel of alert and interaction.

A further embodiment of the present invention is a system and method forautomated remote patient care using patient information retrieved from amedical device adapted to be implanted in a patient. One or more patientcare records are organized in a database with each patient care recordincluding a plurality of the collected measures sets. Each collectedmeasures set include individual measures which each relate to patientinformation recorded by a medical device adapted to be implanted for anindividual patient. A set of the collected measures periodically sentfrom the implantable medical device over a communications link isreceived. The collected measures set is stored into the patient carerecord in the database for the individual patient. One or more of thecollected measures sets in the patient care record for the individualpatient are analyzed relative to one or more other collected measuressets stored in the patient care record of the individual patient.Feedback based on the analysis of the one or more collected measuressets is sent to the individual patient over a feedback communicationslink.

A further embodiment of the present invention is a system and method forautomated remote patient care using patient information retrieved from amedical device adapted to be implanted in a patient. A plurality ofpatient care records is organized in a database with each patient carerecord including a plurality of the collected measures sets. Eachcollected measures set includes individual measures which each relate topatient information recorded by a medical device adapted to be implantedfor an individual patient. A set of the collected measures periodicallysent from the implantable medical device over a communications link isreceived. The collected measures set is stored into the patient carerecord in the database for the individual patient. One or more of thecollected measures sets in the patient care record for the individualpatient is analyzed relative to one or more other collected measuressets stored in other patient care records in the database. Feedbackbased on the analysis of the one or more collected measures sets is sentto the individual patient over a feedback communications link.

A further embodiment of the present invention is a system and method forautomated remote cardiac patient care using cardiovascular patientinformation retrieved from a cardiac monitoring device adapted to beimplanted in a patient. A set of collected cardiovascular measuresrecorded by and stored in the cardiac monitoring device adapted to beimplanted is retrieved on a substantially regular basis and thecollected cardiovascular measures set are periodically communicated overa communications link to a centralized server. The collectedcardiovascular measures set is stored into a patient care record for theindividual patient in a database coupled to the centralized server. Aplurality of patient care records is organized in the database with eachpatient care record including a plurality of the collectedcardiovascular measures sets. Each collected cardiovascular measures setincludes individual cardiovascular measures which each relate to patientinformation recorded by the cardiac monitoring device for an individualpatient. One or more of the collected cardiovascular measures sets inthe patient care record for the individual patient is analyzed relativeto one or more other collected cardiovascular measures sets stored inthe patient care records in the database. Feedback based on the analysisof the one or more collected cardiovascular measures sets is sent to theindividual patient over a feedback communications link.

The present invention facilitates the gathering, storage, and analysisof critical patient information obtained on a routine basis and analyzedin an automated manner. Thus, the burden on physicians and trainedpersonnel to evaluate the volumes of information is significantlyminimized while the benefits to patients are greatly enhanced.

Still other embodiments of the present invention will become readilyapparent to those skilled in the art from the following detaileddescription, wherein is described embodiments of the invention by way ofillustrating the best mode contemplated for carrying out the invention.As will be realized, the invention is capable of other and differentembodiments and its several details are capable of modifications invarious obvious respects, all without departing from the spirit and thescope of the present invention. Accordingly, the drawings and detaileddescription are to be regarded as illustrative in nature and not asrestrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a system for automated collection andanalysis of patient information retrieved from an implantable medicaldevice for remote patient care in accordance with the present invention;

FIG. 2 is a block diagram showing the hardware components of the serversystem of the system of FIG. 1;

FIG. 3 is a block diagram showing the software modules of the serversystem of the system of FIG. 1;

FIG. 4 is a block diagram showing the analysis module of the serversystem of FIG. 3;

FIG. 5 is a database schema showing, by way of example, the organizationof a cardiac patient care record stored in the database of the system ofFIG. 1;

FIG. 6 is a record view showing, by way of example, a set of partialcardiac patient care records stored in the database of the system ofFIG. 1;

FIG. 7 is a flow diagram showing a method for automated collection andanalysis of patient information retrieved from an implantable medicaldevice for remote patient care in accordance with the present invention;

FIG. 8 is a flow diagram showing a routine for analyzing collectedmeasures sets for use in the method of FIG. 7;

FIG. 9 is a flow diagram showing a routine for comparing siblingcollected measures sets for use in the routine of FIG. 8;

FIGS. 10A and 10B are flow diagrams showing a routine for comparing peercollected measures sets for use in the routine of FIG. 8; and

FIG. 11 is a flow diagram showing a routine for providing feedback foruse in the method of FIG. 7.

DETAILED DESCRIPTION

FIG. 1 is a block diagram showing a system 10 for automated collectionand analysis of patient information retrieved from an implantablemedical device for remote patient care in accordance with the presentinvention. A patient 11 is a recipient of an implantable medical device12, such as, by way of example, an IPG or a heart failure or eventmonitor, with a set of leads extending into his or her heart. Theimplantable medical device 12 includes circuitry for recording into ashort-term, volatile memory telemetered signals, which are stored as aset of collected measures for later retrieval.

For an exemplary cardiac implantable medical device, the telemeteredsignals non-exclusively present patient information relating to: atrialelectrical activity, ventricular electrical activity, time of day,activity level, cardiac output, oxygen level, cardiovascular pressuremeasures, the number and types of interventions made, and the relativesuccess of any interventions made on a per heartbeat or binned averagebasis, plus the status of the batteries and programmed settings.Examples of pacemakers suitable for use in the present invention includethe Discovery line of pacemakers, manufactured by Guidant Corporation,Indianapolis, Ind. Examples of ICDs suitable for use in the presentinvention include the Ventak line of ICDs, also manufactured by GuidantCorporation, Indianapolis, Ind.

In the described embodiment, the patient 11 has a cardiac implantablemedical device. However, a wide range of related implantable medicaldevices are used in other areas of medicine and a growing number ofthese devices are also capable of measuring and recording patientinformation for later retrieval. These implantable medical devicesinclude monitoring and therapeutic devices for use in metabolism,endocrinology, hematology, neurology, muscularology,gastro-intestinalogy, genital-urology, ocular, auditory, and similarmedical subspecialties. One skilled in the art would readily recognizethe applicability of the present invention to these related implantablemedical devices.

On a regular basis, the telemetered signals stored in the implantablemedical device 12 are retrieved. By way of example, a programmer 14 canbe used to retrieve the telemetered signals. However, any form ofprogrammer, interrogator, recorder, monitor, or telemetered signalstransceiver suitable for communicating with an implantable medicaldevice 12 could be used, as is known in the art. In addition, a personalcomputer or digital data processor could be interfaced to theimplantable medical device 12, either directly or via a telemeteredsignals transceiver configured to communicate with the implantablemedical device 12.

Using the programmer 14, a magnetized reed switch (not shown) within theimplantable medical device 12 closes in response to the placement of awand 13 over the location of the implantable medical device 12. Theprogrammer 14 communicates with the implantable medical device 12 via RFsignals exchanged through the wand 14. Programming or interrogatinginstructions are sent to the implantable medical device 12 and thestored telemetered signals are downloaded into the programmer 14. Oncedownloaded, the telemetered signals are sent via an internet 15, such asthe Internet, to a server system 16 which periodically receives andstores the telemetered signals in a database 17, as further describedbelow with reference to FIG. 2.

An example of a programmer 14 suitable for use in the present inventionis the Model 2901 Programmer Recorder Monitor, manufactured by GuidantCorporation, Indianapolis, Ind., which includes the capability to storeretrieved telemetered signals on a proprietary removable floppydiskette. The telemetered signals could later be electronicallytransferred using a personal computer or similar processing device tothe internetwork 15, as is known in the art.

Other alternate telemetered signals transfer means could also beemployed. For instance, the stored telemetered signals could beretrieved from the implantable medical device 12 and electronicallytransferred to the internetwork 15 using the combination of a remoteexternal programmer and analyzer and a remote telephonic communicator,such as described in U.S. Pat. No. 5,113,869, the disclosure of which isincorporated herein by reference. Similarly, the stored telemeteredsignals could be retrieved and remotely downloaded to the server system16 using a world-wide patient location and data telemetry system, suchas described in U.S. Pat. No. 5,752,976, the disclosure of which isincorporated herein by reference.

The received telemetered signals are analyzed by the server system 16,which generates a patient status indicator. The feedback is thenprovided back to the patient 11 through a variety of means. By way ofexample, the feedback can be sent as an electronic mail messagegenerated automatically by the server system 16 for transmission overthe internetwork 15. The electronic mail message is received by personalcomputer 18 (PC) situated for local access by the patient 11.Alternatively, the feedback can be sent through a telephone interfacedevice 19 as an automated voice mail message to a telephone 21 or as anautomated facsimile message to a facsimile machine 22, both alsosituated for local access by the patient 11. In addition to a personalcomputer 18, telephone 21, and facsimile machine 22, feedback could besent to other related devices, including a network computer, wirelesscomputer, personal data assistant, television, or digital dataprocessor. Preferably, the feedback is provided in a tiered fashion, asfurther described below with reference to FIG. 3.

FIG. 2 is a block diagram showing the hardware components of the serversystem 16 of the system 10 of FIG. 1. The server system 16 consists ofthree individual servers: network server 31, database server 34, andapplication server 35. These servers are interconnected via anintranetwork 33. In the described embodiment, the functionality of theserver system 16 is distributed among these three servers for efficiencyand processing speed, although the functionality could also be performedby a single server or cluster of servers. The network server 31 is theprimary interface of the server system 16 onto the internetwork 15. Thenetwork server 31 periodically receives the collected telemeteredsignals sent by remote implantable medical devices over the internetwork15. The network server 31 is interfaced to the internetwork 15 through arouter 32. To ensure reliable data exchange, the network server 31implements a TCP/IP protocol stack, although other forms of networkprotocol stacks are suitable.

The database server 34 organizes the patient care records in thedatabase 17 and provides storage of and access to information held inthose records. A high volume of data in the form of collected measuressets from individual patients is received. The database server 34 freesthe network server 31 from having to categorize and store the individualcollected measures sets in the appropriate patient care record.

The application server 35 operates management applications and performsdata analysis of the patient care records, as further described belowwith reference to FIG. 3. The application server 35 communicatesfeedback to the individual patients either through electronic mail sentback over the internetwork 15 via the network server 31 or as automatedvoice mail or facsimile messages through the telephone interface device19.

The server system 16 also includes a plurality of individualworkstations 36 (WS) interconnected to the intranetwork 33, some ofwhich can include peripheral devices, such as a printer 37. Theworkstations 36 are for use by the data management and programmingstaff, nursing staff, office staff, and other consultants and authorizedpersonnel.

The database 17 consists of a high-capacity storage medium configured tostore individual patient care records and related health careinformation. Preferably, the database 17 is configured as a set ofhigh-speed, high capacity hard drives, such as organized into aRedundant Array of Inexpensive Disks (RAID) volume. However, any form ofvolatile storage, non-volatile storage, removable storage, fixedstorage, random access storage, sequential access storage, permanentstorage, erasable storage, and the like would be equally suitable. Theorganization of the database 17 is further described below withreference to FIG. 3.

The individual servers and workstations are general purpose, programmeddigital computing devices consisting of a central processing unit (CPU),random access memory (RAM), non-volatile secondary storage, such as ahard drive or CD ROM drive, network interfaces, and peripheral devices,including user interfacing means, such as a keyboard and display.Program code, including software programs, and data are loaded into theRAM for execution and processing by the CPU and results are generatedfor display, output, transmittal, or storage. In the describedembodiment, the individual servers are Intel Pentium-based serversystems, such as available from Dell Computers, Austin, Tex., or CompaqComputers, Houston, Tex. Each system is preferably equipped with 128 MBRAM, 100GB hard drive capacity, data backup facilities, and relatedhardware for interconnection to the intranetwork 33 and 5 internetwork15. In addition, the workstations 36 are also Intel Pentium-basedpersonal computer or workstation systems, also available from DellComputers, Austin, Tex., or Compaq Computers, Houston, Tex. Eachworkstation is preferably equipped with 64 MB RAM, 10 GB hard drivecapacity, and related hardware for interconnection to the intranetwork33. Other types of server and workstation systems, including personalcomputers, minicomputers, mainframe computers, supercomputers, parallelcomputers, workstations, digital data processors and the like would beequally suitable, as is known in the art.

The telemetered signals are communicated over an internetwork 15, suchas the Internet. However, any type of electronic communications linkcould be used, including an intranetwork link, serial link, datatelephone link, satellite link, radio-frequency link, infrared link,fiber optic link, coaxial cable link, television link, and the like, asis known in the art. Also, the network server 31 is interfaced to theinternetwork 15 using a T-1 network router 32, such as manufactured byCisco Systems, Inc., San Jose, Calif. However, any type of interfacingdevice suitable for interconnecting a server to a network could be used,including a data modem, cable modem, network interface, serialconnection, data port, hub, frame relay, digital PBX, and the like, asis known in the art.

FIG. 3 is a block diagram showing the software modules of the serversystem 16 of the system 10 of FIG. 1. Each module is a computer programwritten as source code in a conventional programming language, such asthe C or Java programming languages, and is presented for execution bythe CPU as object or byte code, as is known in the arts. The variousimplementations of the source code and object and byte codes can be heldon a computer-readable storage medium or embodied on a transmissionmedium in a carrier wave. There are three basic software modules, whichfunctionally define the primary operations performed by the serversystem 16: database module 51, analysis module 53, and feedback module55. In the described embodiment, these modules are executed in adistributed computing environment, although a single server or a clusterof servers could also perform the functionality of the modules. Themodule functions are further described below in more detail beginningwith reference to FIG. 7.

For each patient being provided remote patient care, the server system16 periodically receives a collected measures set 50 which is forwardedto the database module 51 for processing. The database module 51organizes the individual patent care records stored in the database 52and provides the facilities for efficiently storing and accessing thecollected measures sets 50 and patient data maintained in those records.An exemplary database schema for use in storing collected measures sets50 in a patient care record is described below, by way of example, withreference to FIG. 5. The database server 34 (shown in FIG. 2) performsthe functionality of the database module 51. Any type of databaseorganization could be utilized, including a flat file system,hierarchical database, relational database, or distributed database,such as provided by database vendors, such as Oracle Corporation,Redwood Shores, Calif.

The analysis module 53 analyzes the collected measures sets 50 stored inthe patient care records in the database 52. The analysis module 53makes an automated determination of patient wellness in the form of apatient status indicator 54. Collected measures sets 50 are periodicallyreceived from implantable medical devices and maintained by the databasemodule 51 in the database 52. Through the use of this collectedinformation, the analysis module 53 can continuously follow the medicalwell being of a patient and can recognize any trends in the collectedinformation that might warrant medical intervention. The analysis module53 compares individual measures and derived measures obtained from boththe care records for the individual patient and the care records for adisease specific group of patients or the patient population in general.The analytic operations performed by the analysis module 53 are furtherdescribed below with reference to FIG. 4. The application server 35(shown in FIG. 2) performs the functionality of the analysis module 53.

The feedback module 55 provides automated feedback to the individualpatient based, in part, on the patient status indicator 54. As describedabove, the feedback could be by electronic mail or by automated voicemail or facsimile. Preferably, the feedback is provided in a tieredmanner. In the described embodiment, four levels of automated feedbackare provided. At a first level, an interpretation of the patient statusindicator 54 is provided. At a second level, a notification of potentialmedical concern based on the patient status indicator 54 is provided.This feedback level could also be coupled with human contact byspecially trained technicians or medical personnel. At a third level,the notification of potential medical concern is forwarded to medicalpractitioners located in the patient's geographic area. Finally, at afourth level, a set of reprogramming instructions based on the patientstatus indicator 54 could be transmitted directly to the implantablemedical device to modify the programming instructions contained therein.As is customary in the medical arts, the basic tiered feedback schemewould be modified in the event of bona fide medical emergency. Theapplication server 35 (shown in FIG. 2) performs the functionality ofthe feedback module 55.

FIG. 4 is a block diagram showing the analysis module 53 of the serversystem 16 of FIG. 3. The analysis module 53 contains two functionalsubmodules: comparison module 62 and derivation module 63. The purposeof the comparison module 62 is to compare two or more individualmeasures, either collected or derived. The purpose of the derivationmodule 63 is to determine a derived measure based on one or morecollected measures which is then used by the comparison module 62. Forinstance, a new and improved indicator of impending heart failure couldbe derived based on the exemplary cardiac collected measures setdescribed with reference to FIG. 5. The analysis module 53 can operateeither in a batch mode of operation wherein patient status indicatorsare generated for a set of individual patients or in a dynamic modewherein a patient status indicator is generated on the fly for anindividual patient.

The comparison module 62 receives as inputs from the database 17 twoinput sets functionally defined as peer collected measures sets 60 andsibling collected measures sets 61, although in practice, the collectedmeasures sets are stored on a per sampling basis. Peer collectedmeasures sets 60 contain individual collected measures sets that allrelate to the same type of patient information, for instance, atrialelectrical activity, but which have been periodically collected overtime. Sibling collected measures sets 61 contain individual collectedmeasures sets that relate to different types of patient information, butwhich may have been collected at the same time or different times. Inpractice, the collected measures sets are not separately stored as“peer” and “sibling” measures. Rather, each individual patient carerecord stores multiple sets of sibling collected measures. Thedistinction between peer collected measures sets 60 and siblingcollected measures sets 61 is further described below with reference toFIG. 6.

The derivation module 63 determines derived measures sets 64 on anas-needed basis in response to requests from the comparison module 62.The derived measures 64 are determined by performing linear andnon-linear mathematical operations on selected peer measures 60 andsibling measures 61, as is known in the art.

FIG. 5 is a database schema showing, by way of example, the organizationof a cardiac patient care record stored 70 in the database 17 of thesystem 10 of FIG. 1. Only the information pertaining to collectedmeasures sets are shown. Each patient care record would also containnormal identifying and treatment profile information, as well as medicalhistory and other pertinent data (not shown). Each patient care recordstores a multitude of collected measures sets for an individual patient.Each individual set represents a recorded snapshot of telemeteredsignals data which was recorded, for instance, per heartbeat or binnedaverage basis by the implantable medical device 12. For example, for acardiac patient, the following information would be recorded as acollected measures set: atrial electrical activity 71, ventricularelectrical activity 72, time of day 73, activity level 74, cardiacoutput 75, oxygen level 76, cardiovascular pressure measures 77,pulmonary measures 78, interventions made by the implantable medicaldevice 78, and the relative success of any interventions made 80. Inaddition, the implantable medical device 12 would also communicatedevice specific information, including battery status 81 and programsettings 82. Other types of collected measures are possible. Inaddition, a well-documented set of derived measures can be determinedbased on the collected measures, as is known in the art.

FIG. 6 is a record view showing, by way of example, a set of partialcardiac patient care records stored in the database 17 of the system 10of FIG. 1. Three patient care records are shown for Patient 1, Patient2, and Patient 3. For each patent, three sets of measures are shown, XY, and Z. The measures are organized into sets with Set 0 representingsibling measures made at a reference time t=0. Similarly, Set n-2, Setn-1 and Set n each represent sibling measures made at later referencetimes t=n-2, t=n-1 and t=n, respectively.

For a given patient, for instance, Patient 1, all measures representingthe same type of patient information, such as measure X, are peermeasures. These are measures, which are monitored over time in adisease-matched peer group. All measures representing different types ofpatient information, such as measures X, Y, and Z, are sibling measures.These are measures which are also measured over time, but which mighthave medically significant meaning when compared to each other within asingle set. Each of the measures, X, Y, and Z, could be either collectedor derived measures.

The analysis module 53 (shown in FIG. 4) performs two basic forms ofcomparison. First, individual measures for a given patient can becompared to other individual measures for that same patient. Thesecomparisons might be peer-to-peer measures projected over time, forinstance, X_(n), X_(n-1), X_(n-2), . . . X₀, or sibling-to-siblingmeasures for a single snapshot, for instance, X_(n), Y_(n), and Z_(n),or projected over time, for instance, X_(n), Y_(n), Z_(n), X_(n-1),Y_(n-1), Z_(n-1), X_(n-2), Y_(n-2), Z_(n-2), . . . X₀, Y₀, Z₀. Second,individual measures for a given patient can be compared to otherindividual measures for a group of other patients sharing the samedisease-specific characteristics or to the patient population ingeneral. Again, these comparisons might be peer-to-peer measuresprojected over time, for instance, X_(n), X_(n′), X_(n″), X_(n-1),X_(n-1′), X_(n-1″), X_(n-2), X_(n-2′), X_(n-2″). . . X₀, X_(0′), X_(″),or comparing the individual patient's measures to an average from thegroup. Similarly, these comparisons might be sibling-to-sibling measuresfor single snapshots, for instance, X_(n), X_(n′), X_(n″), Y_(n),Y_(n′), Y_(n″), and Z_(n), Z_(n′), Z_(n″), or projected over time, forinstance, X_(n), X_(n′), X_(n″), Y_(n), Y_(n′), Y_(n″), Z_(n), Z_(n′),Z_(n″), X_(n-1), X_(n-1′), X_(n-1″), Y_(n-1), Y_(n-1′), Y_(n-1″),Z_(n-1), Z_(n-1′), Z_(n-1″), X_(n-2), X_(n-2′), X_(n-2″), Y_(n-2),Y_(n-2′), Y_(n-2″, Z) _(n-2), Z_(n-2′), Z_(n-2″). . . X₀, X_(0′),X_(0″), Y₀, Y_(0′), Y_(0″), and Z₀, Z_(0′), Z_(0″). Other forms ofcomparisons are feasible.

FIG. 7 is a flow diagram showing a method 90 for automated collectionand analysis of patient information retrieved from an implantablemedical device 12 for remote patient care in accordance with the presentinvention. The method 90 is implemented as a conventional computerprogram for execution by the server system 16 (shown in FIG. 1). As apreparatory step, the patient care records are organized in the database17 with a unique patient care record assigned to each individual patient(block 91). Next, the collected measures sets for an individual patientare retrieved from the implantable medical device 12 (block 92) using aprogrammer, interrogator, telemetered signals transceiver, and the like.The retrieved collected measures sets are sent, on a substantiallyregular basis, over the internetwork 15 or similar communications link(block 93) and periodically received by the server system 16 (block 94).The collected measures sets are stored into the patient care record inthe database 17 for that individual patient (block 95). One or more ofthe collected measures sets for that patient are analyzed (block 96), asfurther described below with reference to FIG. 8. Finally, feedbackbased on the analysis is sent to that patient over the internetwork 15as an email message, via telephone line as an automated voice mail orfacsimile message, or by similar feedback communications link (block97), as further described below with reference to FIG. 11.

FIG. 8 is a flow diagram showing the routine for analyzing collectedmeasures sets 96 for use in the method of FIG. 7. The purpose of thisroutine is to make a determination of general patient wellness based oncomparisons and heuristic trends analyses of the measures, bothcollected and derived, in the patient care records in the database 17. Afirst collected measures set is selected from a patient care record inthe database 17 (block 100). If the measures comparison is to be made toother measures originating from the patient care record for the sameindividual patient (block 101), a second collected measures set isselected from that patient care record (block 102). Otherwise, a groupmeasures comparison is being made (block 101) and a second collectedmeasures set is selected from another patient care record in thedatabase 17 (block 103). Note the second collected measures set couldalso contain averaged measures for a group of disease specific patientsor for the patient population in general.

Next, if a sibling measures comparison is to be made (block 104), aroutine for comparing sibling collected measures sets is performed(block 105), as further described below with reference to FIG. 9.Similarly, if a peer measures comparison is to be made (block 106), aroutine for comparing sibling collected measures sets is performed(block 107), as farther described below with reference to FIGS. 10A and10B.

Finally, a patient status indicator is generated (block 108). By way ofexample, cardiac output could ordinarily be approximately 5.0 liters perminute with a standard deviation of ±1.0. An actionable medicalphenomenon could occur when the cardiac output of a patient is ±3.0−4.0standard deviations out of the norm. A comparison of the cardiac outputmeasures 75 (shown in FIG. 5) for an individual patient against previouscardiac output measures 75 would establish the presence of any type ofdownward health trend as to the particular patient. A comparison of thecardiac output measures 75 of the particular patient to the cardiacoutput measures 75 of a group of patients would establish whether thepatient is trending out of the norm. From this type of analysis, theanalysis module 53 generates a patient status indicator 54 and othermetrics of patient wellness, as is known in the art.

FIG. 9 is a flow diagram showing the routine for comparing siblingcollected measures sets 105 for use in the routine of FIG. 8. Siblingmeasures originate from the patient care records for an individualpatient. The purpose of this routine is either to compare siblingderived measures to sibling derived measures (blocks 111-113) or siblingcollected measures to sibling collected measures (blocks 115-117). Thus,if derived measures are being compared (block 110), measures areselected from each collected measures set (block 111). First and secondderived measures are derived from the selected measures (block 112)using the derivation module 63 (shown in FIG. 4). The first and secondderived measures are then compared (block 113) using the comparisonmodule 62 (also shown in FIG. 4). The steps of selecting, determining,and comparing (blocks 111-113) are repeated until no further comparisonsare required (block 114), whereupon the routine returns.

If collected measures are being compared (block 110), measures areselected from each collected measures set (block 115). The first andsecond collected measures are then compared (block 116) using thecomparison module 62 (also shown in FIG. 4). The steps of selecting andcomparing (blocks 115-116) are repeated until no further comparisons arerequired (block 117), whereupon the routine returns.

FIGS. 10A and 10B are a flow diagram showing the routine for comparingpeer collected measures sets 107 for use in the routine of FIG. 8. Peermeasures originate from patient care records for different patients,including groups of disease specific patients or the patient populationin general. The purpose of this routine is to compare peer derivedmeasures to peer derived measures (blocks 122-125), peer derivedmeasures to peer collected measures (blocks 126-129), peer collectedmeasures to peer derived measures (block 131-134), or peer collectedmeasures to peer collected measures (blocks 135-137). Thus, if the firstmeasure being compared is a derived measure (block 120) and the secondmeasure being compared is also a derived measure (block 121), measuresare selected from each collected measures set (block 122). First andsecond derived measures are derived from the selected measures (block123) using the derivation module 63 (shown in FIG. 4). The first andsecond derived measures are then compared (block 124) using thecomparison module 62 (also shown in FIG. 4). The steps of selecting,determining, and comparing (blocks 122-124) are repeated until nofurther comparisons are required (block 115), whereupon the routinereturns.

If the first measure being compared is a derived measure (block 120) butthe second measure being compared is a collected measure (block 121), afirst measure is selected from the first collected measures set (block126). A first derived measure is derived from the first selected measure(block 127) using the derivation module 63 (shown in FIG. 4). The firstderived and second collected measures are then compared (block 128)using the comparison module 62 (also shown in FIG. 4). The steps ofselecting, determining, and comparing (blocks 126-128) are repeateduntil no further comparisons are required (block 129), whereupon theroutine returns.

If the first measure being compared is a collected measure (block 120)but the second measure being compared is a derived measure (block 130),a second measure is selected from the second collected measures set(block 131). A second derived measure is derived from the secondselected measure (block 132) using the derivation module 63 (shown inFIG. 4). The first collected and second derived measures are thencompared (block 133) using the comparison module 62 (also shown in FIG.4). The steps of selecting, determining, and comparing (blocks 131-133)are repeated until no further comparisons are required (block 134),whereupon the routine returns.

If the first measure being compared is a collected measure (block 120)and the second measure being compared is also a collected measure (block130), measures are selected from each collected measures set (block135). The first and second collected measures are then compared (block136) using the comparison module 62 (also shown in FIG. 4). The steps ofselecting and comparing (blocks 135-136) are repeated until no furthercomparisons are required (block 137), whereupon the routine returns.

FIG. 11 is a flow diagram showing the routine for providing feedback 97for use in the method of FIG. 7. The purpose of this routine is toprovide tiered feedback based on the patient status indicator. Fourlevels of feedback are provided with increasing levels of patientinvolvement and medical care intervention. At a first level (block 150),an interpretation of the patient status indicator 54, preferably phrasedin lay terminology, and related health care information is sent to theindividual patient (block 151) using the feedback module 55 (shown inFIG. 3). At a second level (block 152), a notification of potentialmedical concern, based on the analysis and heuristic trends analysis, issent to the individual patient (block 153) using the feedback module 55.At a third level (block 154), the notification of potential medicalconcern is forwarded to the physician responsible for the individualpatient or similar health care professionals (block 155) using thefeedback module 55. Finally, at a fourth level (block 156),reprogramming instructions are sent to the implantable medical device 12(block 157) using the feedback module 55.

Therefore, through the use of the collected measures sets, the presentinvention makes possible immediate access to expert medical care at anytime and in any place. For example, after establishing and registeringfor each patient an appropriate baseline set of measures, the databaseserver could contain a virtually up-to-date patient history, which isavailable to medical providers for the remote diagnosis and preventionof serious illness regardless of the relative location of the patient ortime of day.

Moreover, the gathering and storage of multiple sets of critical patientinformation obtained on a routine basis makes possible treatmentmethodologies based on an algorithmic analysis of the collected datasets. Each successive introduction of a new collected measures set intothe database server would help to continually improve the accuracy andeffectiveness of the algorithms used. In addition, the present inventionpotentially enables the detection, prevention, and cure of previouslyunknown forms of disorders based on a trends analysis and by across-referencing approach to create continuously improving peer-groupreference databases.

Finally, the present invention makes possible the provision of tieredpatient feedback based on the automated analysis of the collectedmeasures sets. This type of feedback system is suitable for use in, forexample, a subscription based health care service. At a basic level,informational feedback can be provided by way of a simple interpretationof the collected data. The feedback could be built up to provide agradated response to the patient, for example, to notify the patientthat he or she is trending into a potential trouble zone. Humaninteraction could be introduced, both by remotely situated and localmedical practitioners. Finally, the feedback could include directinterventive measures, such as remotely reprogramming a patient's IPG.

While the invention has been particularly shown and described asreferenced to the embodiments thereof, those skilled in the art willunderstand that the foregoing and other changes in form and detail maybe made therein without departing from the spirit and scope of theinvention.

What is claimed is:
 1. A system for automated remote patient care usingpatient information retrieved from a medical device adapted to beimplanted in a patient, comprising: a medical device adapted to beimplanted in an individual patient and being interfaced to acommunication link, the implantable medical device periodically sendinga set of collected measurement for the individual patient over thecommunication link; a database organized into one or more patient carerecords with each patient care record comprising a plurality of thecollected measurements sets, each collected measurements set comprisingindividual measurements which each relate to patient informationrecorded by the implantable medical device; and a server coupled to thedatabase and interfaced to the communications link and a feedbackcommunications link, the server comprising: a database module storingthe collected measurements set received from the implantable medicaldevice over the communications link into the patient care record in thedatabase for the individual patient; an analysis module analyzing one ormore of the collected measurements sets in the patient care record forthe individual patient relative to one or more other collectedmeasurements sets stored in the patient care record of the individualpatient; and a feedback module sending feedback based on the analysis ofthe one or more collected measurements sets to the individual patientover the feedback communications link.
 2. A system according to claim 1,the analysis module further comprising: a comparison module comparing atleast one collected measurement selected from the one or more collectedmeasurements sets to at least one other collected measurement selectedfrom the one or more other collected measurements sets, the at least onecollected measurement and the at least one other collected measurementboth relating to the same type of patient information.
 3. A systemaccording to claim 1, the analysis module further comprising: acomparison module comparing at least one collected measurement selectedfrom the one or more collected measurements sets to at least one othermeasurement selected from the one or more other collected measurementssets, that at least one collected measurement and the at least one othercollected measurement both relating to different types of patientinformation.
 4. A system according to claim 1, the analysis modulefurther comprising: a derivation module determining at least one derivedmeasurement using at least one collected measurement selected from atleast one of the one or more collected measurements sets and the one ormore other collected measurements sets; and a comparison modulecomparing the at least one derived measurement to at least onemeasurement selected from at least one of the one or more collectedmeasurements sets and the one or more other collected measurements sets.5. A system according to claim 1, the analysis module furthercomprising: a derivation module determining at least one derivedmeasurement using at least one collected measurement selected from atleast one of the one or more collected measurements sets and the one ormore other collected measurements sets and determining at least oneother derived measurement using at least one collected measurementselected from at least one of the one or more collected measurementssets and the one or more other collected measurements sets; and acomparison module comparing the at least one derived measurement to theat least one other derived measurement.
 6. A system according to claim1, the feedback module further comprising providing tiered feedbackcomprising: at a first level of feedback, communicating aninterpretation of the analysis of the one or more collected measurementssets to the individual patient over the feedback communications link; ata second level of feedback, communicating a notification of potentialmedical concern based on the analysis of the one or more collectedmeasurements sets to the individual patient over the feedbackcommunications link; at a third level of feedback, communicating anotification of potential medical concern based on the analysis of theone or more collected measurement sets to medical personnel in localproximity to the individual patient over the feedback communicationslink; and at a fourth level of feedback, communicating a set ofreprogramming instruction based on analysis of the one or more collectedmeasurements sets to the implantable medical device over the feedbackcommunications link.
 7. A method for automated remote patient care usingpatient information retrieved from a medical device adapted to beimplanted in a patient, comprising: organizing one or more patient carerecords in a database with each patient care record comprising aplurality of he collected measurements sets, each collected measurementsset comprising individual measurements which each relate to patientinformation recorded by a medical devise adapted to be implanted for anindividual patient; receiving a set of the collected measurementsperiodically sent from the implantable medical device over acommunications link; storing the collected measurements set into thepatient care record in the database for the individual patient;analyzing one or more of the collected measurements sets in the patientcare record for the individual patient relative to one or more othercollected measurements sets stored in the patient care record of theindividual patient; and sending feedback based on the analysis of theone or more collected measurements sets to the individual patient over afeedback communications link.
 8. A method according to claim 7, theoperation of analyzing further comprising: comparing at least onecollected measurement selected from the one or more collectedmeasurements sets to at least one other collected measurement selectedfrom the one or more other collected measurements sets, the at least onecollected measurement and the at least one other collected measurementboth relating to the same type of patient information.
 9. A methodaccording to claim 7, the operation of analyzing further comprising:comparing at least one collected measurement selected from the one ormore collected measurements sets to at least one other collectedmeasurement selected from the one or more other collected measurementssets, the at least one collected measurement and the at least one othercollected measurement both relating to different types of patientinformation.
 10. A method according to claim 7, the operation ofanalyzing further comprising: determining at least one derivedmeasurement using at least one collected measurement selected from atleast one of the one or more collected measurements sets and the one ormore other collected measurements sets; and comparing the at least onederived measurement to at least one measurement selected from at leastone of the one or more collected measurements sets and the one or moreother collected measurements sets.
 11. A method according to claim 7,the operation of analyzing further comprising: determining at least onederived measurement using at least one collected measurement selectedfrom at least one of the one or more collected measurements sets and theone or more other collected measurements sets; determining at least oneother derived measurement using at least one collected measurementcollected from a least one of the one or more collected measurementssets and the one or more other collected measurements sets; andcomparing the at least one derived measurement to the at least one otherderived measurement.
 12. A method according to claim 7, the operation ofsending feedback further comprising: providing tiered feedbackcomprising: at a first level of feedback, communicating aninterpretation of the analysis of the one or more collected measurementssets to the individual patient over the feedback communications link; ata second level of feedback, communicating a notification of potentialmedical concerned based on the analysis of the one or more collectedmeasurements sets to the individual patient over the feedbackcommunications link; at a third level of feedback, communicating anotification of potential medical concern based on the analysis of theone or more collected measurements sets to medical personnel in localproximity to the individual patient over the feedback communicationslink; and at a fourth level of feedback, communicating a set ofreprogramming instructions based on analysis of the one or morecollected measurements sets to the implantable medical device over thefeedback communications link.
 13. A system for automated remote cardiacpatient care using cardiovascular patient information retrieved from acardiac monitoring device adapted to be implanted in a patient,comprising: a telemetry transceiver on a substantially regular basis aset of collected cardiovascular measurements recorded by and stored inthe cardiac monitoring device adapted to be implanted and periodicallycommunicating the collected cardiovascular measurements set over acommunications link to a centralized server; and a centralized servercomprising: a database storing the collected cardiovascular measurementsset into a patient care record for the individual patient, the databasebeing organized into a plurality of patient care records with eachpatient care record comprising a plurality of the collectedcardiovascular measurements sets, each collected cardiovascularmeasurements set comprising individual cardiovascular measurements whicheach relate to patient information recorded by a implantable cardiacmonitoring device for an individual patient; an analysis moduleanalyzing one or more of the collected cardiovascular measurements setsin the patient care record for the individual patient relative to one ormore other collected cardiovascular measurements sets stored in thepatient care records in the database; and a feedback module sendingfeedback based on the analysis of the one or more collectedcardiovascular measurements sets to the individual patient over afeedback communications link.
 14. A method for automated remote cardiacpatient care using cardiovascular patient information retrieved from acardiac monitoring device adapted to be implanted in a patient,comprising: retrieving on a substantially regular basis a set ofcollected cardiovascular measurements recorded by and stored in thecardiac monitoring device adapted to be implanted; periodicallycommunicating the collected cardiovascular measurements set over acommunications link to a centralized server; storing the collectedcardiovascular measurements set into a patient care record for theindividual patient in a database coupled to the centralized server;organizing a plurality of patient care records in the database with eachpatient care record comprising a plurality of the collectedcardiovascular measurements sets, each collected cardiovascularmeasurements set comprising individual cardiovascular measurements whicheach relate to patient information recorded by the cardiac monitoringdevice for an individual patient; analyzing one or more of the collectedcardiovascular measurement sets in the patient care record for theindividual patient relative to one or more other collectedcardiovascular measurements sets stored in the patient care records inthe database; and sending feedback based on the analysis of the one ormore collected cardiovascular measurements sets to the individualpatient over a feedback communications link.